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Does intravenous Δ-9-tetrahydrocannabinol increase dopamine release? A SPET study

Journal Article


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Abstract


  • Intravenous (IV) Delt 9-tetrahydrocannabinol (THC) induces transient psychotic symptoms in healthy subjects and in schizophrenic patients, but the

    psychotomimetic mechanism is unknown. One possibility is that THC stimulates dopamine (DA) release in the striatum. In this study we tested whether

    IV THC led to an increase in striatal DA release compared to placebo. We also investigated whether DA release and positive psychotic symptoms were

    related. Eleven healthy male volunteers completed two 123I-iodobenzamide ([123I]IBZM) single photon emission tomography (SPET) sessions and

    received IV THC (2.5 mg) or placebo in a randomized counterbalanced order, under double-blind conditions. Analysable data were obtained from nine

    participants. The Positive and Negative Syndrome Scale (PANSS) was used to rate psychotomimetic effects. Striatal binding index values were calculated

    using the occipital cortex as a reference region. Both the PANSS positive and general symptoms increased significantly at 30 min following IV THC.

    There were no significant differences in binding index in the caudate or putamen under THC compared to placebo conditions. Positive psychotic

    symptoms and DA release were unrelated. THC did not lead to a significant increase in DA release even though the dose was sufficient for participants to

    have psychotic symptoms. These findings do not support a central role for striatal DA in THC-elicited psychosis.

Authors


  •   Barkus, Emma
  •   Morrison, Paul (external author)
  •   Vuletic, D (external author)
  •   Dickson, J.C. (external author)
  •   Ell, Peter J. (external author)
  •   Pilowsky, L.S. (external author)
  •   Brenneisen, Rudolf (external author)
  •   Holt, David W. (external author)
  •   Powel, J (external author)
  •   Kapur, S (external author)
  •   Murray, Robin (external author)

Publication Date


  • 2011

Citation


  • Barkus, E., Morrison, P., Vuletic, D., Dickson, J., Ell, P., Pilowsky, L., Brenneisen, R., Holt, D., Powel, J., Kapur, S. & Murray, R. (2011). Does intravenous Δ-9-tetrahydrocannabinol increase dopamine release? A SPET study. Journal of Psychopharmacology, 25 (11), 1462-1468.

Scopus Eid


  • 2-s2.0-82955215765

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=2143&context=hbspapers

Ro Metadata Url


  • http://ro.uow.edu.au/hbspapers/1094

Has Global Citation Frequency


Number Of Pages


  • 6

Start Page


  • 1462

End Page


  • 1468

Volume


  • 25

Issue


  • 11

Place Of Publication


  • United Kingdom

Abstract


  • Intravenous (IV) Delt 9-tetrahydrocannabinol (THC) induces transient psychotic symptoms in healthy subjects and in schizophrenic patients, but the

    psychotomimetic mechanism is unknown. One possibility is that THC stimulates dopamine (DA) release in the striatum. In this study we tested whether

    IV THC led to an increase in striatal DA release compared to placebo. We also investigated whether DA release and positive psychotic symptoms were

    related. Eleven healthy male volunteers completed two 123I-iodobenzamide ([123I]IBZM) single photon emission tomography (SPET) sessions and

    received IV THC (2.5 mg) or placebo in a randomized counterbalanced order, under double-blind conditions. Analysable data were obtained from nine

    participants. The Positive and Negative Syndrome Scale (PANSS) was used to rate psychotomimetic effects. Striatal binding index values were calculated

    using the occipital cortex as a reference region. Both the PANSS positive and general symptoms increased significantly at 30 min following IV THC.

    There were no significant differences in binding index in the caudate or putamen under THC compared to placebo conditions. Positive psychotic

    symptoms and DA release were unrelated. THC did not lead to a significant increase in DA release even though the dose was sufficient for participants to

    have psychotic symptoms. These findings do not support a central role for striatal DA in THC-elicited psychosis.

Authors


  •   Barkus, Emma
  •   Morrison, Paul (external author)
  •   Vuletic, D (external author)
  •   Dickson, J.C. (external author)
  •   Ell, Peter J. (external author)
  •   Pilowsky, L.S. (external author)
  •   Brenneisen, Rudolf (external author)
  •   Holt, David W. (external author)
  •   Powel, J (external author)
  •   Kapur, S (external author)
  •   Murray, Robin (external author)

Publication Date


  • 2011

Citation


  • Barkus, E., Morrison, P., Vuletic, D., Dickson, J., Ell, P., Pilowsky, L., Brenneisen, R., Holt, D., Powel, J., Kapur, S. & Murray, R. (2011). Does intravenous Δ-9-tetrahydrocannabinol increase dopamine release? A SPET study. Journal of Psychopharmacology, 25 (11), 1462-1468.

Scopus Eid


  • 2-s2.0-82955215765

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=2143&context=hbspapers

Ro Metadata Url


  • http://ro.uow.edu.au/hbspapers/1094

Has Global Citation Frequency


Number Of Pages


  • 6

Start Page


  • 1462

End Page


  • 1468

Volume


  • 25

Issue


  • 11

Place Of Publication


  • United Kingdom